Biaryl seven-membered lactones (BSLs), the target compounds are a class of bioactive compounds with anti-arrhythmic activity, which also serve as a starting material or structural units for chemical synthesis. To report a simple and efficient procedure for the synthesis of biaryl seven-membered lactones. Under microwave, the umpolung reaction was promoted by N-heterocyclic carbenes under oxygen, with anhydrous potassium carbonate as base and with 1,4,7,10,13,16-Hexanoxacyclooctadecane (18-crown-6) as a phase-transfer catalyst. The practical protocol was found to be compatible with different structurally diverse substrates and with moderate to excellent yields. This synthesis method has the advantage of high efficacy and novelty, short reaction time, operation simplicity, mild condition and high yields, providing a useful and atom-economic approach to the synthesis of BSLs.